{Reference Type}: Case Reports {Title}: Infective Endocarditis of a Rare Etiology of Streptococcus alactolyticus: A Case Report and Literature Review. {Author}: Gherlan GS;Chicos AC;Veja AM;Enyedi M; {Journal}: Cureus {Volume}: 16 {Issue}: 3 {Year}: 2024 Mar 暂无{DOI}: 10.7759/cureus.57332 {Abstract}: Streptococcus alactolyticus is a non-motile Gram-positive, catalase-negative cocci, a part of group D Streptococci. In the literature, S. alactolyticus is documented as a causative agent of infective endocarditis, demonstrated by blood cultures in only four other cases, representing an extremely rare circumstance. Here, we describe a case of infective endocarditis due to S. alactolyticus in a young patient known with a bicuspid aortic valve and associated with a sigmoid precancerous polyp. The patient was also known to have blood hypertension and type II diabetes. Symptoms at the debut appeared insidiously and were non-specific: fatigue, loss of appetite, weight loss, night sweats, and fever. They lasted for the entire period of the illness with transient improvement during the courses of antibiotics. He followed more antibiotic courses prescribed for various clinical diagnoses. Each round of antibiotic treatment transitorily alleviated the symptoms, which reappeared each time after the cessation. The correct diagnosis was made only about three months after the appearance of the first clinical manifestations. This was based on ultrasound criteria (presence of vegetation and lesions of aortic cusps) and microbiological criteria (isolation of S. alactolyticus in blood cultures). A course of six weeks of ceftriaxone was considered the opportune antibiotic therapy. Similar to all other cases described in the literature, our patient presented important damage to the valvular tissue and required cardiac surgery to re-establish the normal function of the valve. The surgery consisted of the excision of the severely affected natural aortic valve and her replacement with a mechanical prosthetic valve. Following medical and surgical treatment, the patient is completely healed and has a normal life. Our case is noteworthy because of the scarcity of the involvement of S. alactolyticus in the pathogeny of infective endocarditis. This is the fifth published case with this etiology, and an overview of all five cases is provided in the article.